7A–38 AUTOMATIC TRANSMISSION (AW30-40LE)
DTC P0727 (FLASHING CODE 13) ENGINE REVOLUTION SIGNAL FAILURE (NE)
D07RY00019Circuit description:
Engine revolution (rpm) signals are sent from Engine
Control Module (ECM) to the Transmission Control
Module (TCM).
The engine speed sensor is an electromagnetic pulse
pickup type that generates signals when the flywheel
gear revolves (2 pulses at a single revolution of the
flywheel gear).
The TCM converts these sine wave signals into engine
revolution (RPM) signals.
Fail-safe control:
The TCM controls fail-safe by detecting engine revolution
sensor failure.
Failure detection:
• When input revolution is more than 2000 rpm
• When not even 1 pulse is input in the engine
revolution signal during 5 seconds
• Detection inhibit condition: At 4th gear
Contents of control:
At failure detection
• Up hill and down hill control inhibit
• Oil temperature sensor failure detection inhibit
• Blinks "CHECK TRANS" lamp
• Stores the failure information in failure memory.
At failure decision
Same as failure detection
Conditions of turning "CHECK TRANS" lamp off:
Turns "CHECK TRANS" lamp off when judged 0km/h by
speed meter sensor after the engine revolution signal
pulses are input 250 pulses normally.
(however, uses 0 km/h judgment by back-up vehicle
speed at output revolution failure)
Reversion conditions from fail-safe:
Recovers at the same time as the conditions of turning
“CHECK TRANS” lamp off are satisfied.Test description:
The following numbers correspond to circled numbers on
the diagnostic char t.
(1) Engine revolution signals are input from the ECM into
the TCM.
(2) When the engine idling, voltage fluctuates with (AC
intermittent) range of less than 1.4V
9 16V.
Diagnostic aids:
An intermittent may be caused by a poor connection,
rubbed through wire insulation or a wire broken inside
the insulation. Inspect related harness connector for
backed out terminals, improper mating, broken locks,
improperly formed or damaged terminals, poor terminal
to wire connection and damaged harness.
